The human eyes and brain are very good at detecting points of interest in a visual image. One way that an object is identified in an image is by the identification of edges within the image. The brain can identify edges of the object by finding points in the image where adjacent pixels exhibit a distinct contrast. Numerous edges in the image combine to create an overall shape. The shape in the image is then compared with the shapes of known objects. If the shape is sufficiently similar to a known object, the brain can identify the object in the image.
Computers cannot process images in the same way as the human brain. Often images lack sufficient detail or contrast for a computer to be able to detect relevant features. Even the fundamental step of identifying the location of edges within an image can be challenging to perform with a computer. Without an adequate identification of the locations of edges in an image, the computer is unable to perform subsequent operations, such as identifying objects or other points of interest within the image.